All QIBA PHANTOMS

• C52 Transducer held in ring stand – verasonics system

• Phantom on turntable – 8 rotation angles• 7 transducer locations • 3 focal depths (40, 60, 80 mm)• SWS estimates:

–Bandpass filter 100-1000 Hz–Ransac algorithm – fov ~ 2 cmx2cm–Error bars mean +/- 1 std. dev from 56 measures

Results

1786-X

1787-X

40

6080

Sim Results – Lateral Regression Window Location

Window positionsBlue 0-12 mmRed 1-12Green 2-12Black 4-12

•Conclusion – you must be outside the ROE (near field of shear wave) to get consistent speeds •Also- depth dependence here was within numerical error???